Advanced liquid vortex separation system

ABSTRACT

A liquid vortex separator including a vortex tube ( 16 ) with an impeller ( 13 ) in the feed end to impart a rotational motion to liquid within the tube, a feed cylinder ( 12 ) connected to the vortex tube by a reducing cone ( 14 ). The separator has a separating cone ( 17 ) at the outlet end, an annular collecting ring ( 18 ) for heavy solids and a liquid discharge pipe extending axially from the separating cone. A feed tank ( 31 ) and circulating stream arrangement ensures operation of the system at varying feed rates. The liquid vortex separator may also be fitted with microwave generators ( 40 ), electrodes ( 51 )powered from a DC source or magnets ( 60 ) to produce desired effects or chemical reactions in the material being processed through the liquid vortex separator.

FIELD OF INVENTION

This invention relates to a liquid vortex separation system for theseparation of solids and liquids, gas and liquids or liquids ofdifferent specific gravity.

BACKGROUND TO THE INVENTION

Comminution in the mineral processing industry consists of coarse andfine crushing followed by grinding in a ball mill and size separation bypump and hydrocyclone. This conventional method of size separationrequires a pump and hydrocyclone to carry out the separation. Thismethod consumes a high amount of energy and wear on the pump. U.S. Pat.Nos. 4,555,253 and 4,475,932 of Hull, et al (Nov. 16, 1985 and Oct. 9,1984) describe a gas-liquid separation system using a circulating pumpand creating a vortex in the separator.

The liquid vortex separator introduces the separating force directlyinto one unit. Rotational motion is imparted to the feed liquid by animpeller at the feed end of the tube and the light and heavy productsare collected at the discharge end. The impeller is simple inconstruction and clearances required are less critical than in a slurrypump, making the liquid vortex separator requiring less maintenanceresulting in a more reliable unit.

PRIOR ART

A conventional liquid vortex separator is shown on FIG. 1. It isbasically a cylinder 1 with an impeller 2 and feed inlet 3 at one endand a conical separator tube 4 at the other end where the separatedproducts are discharged. The impeller imparts a rotating motion to thefeed slurry and this rotating motion continues as the slurry travelstowards the discharge end. The heavier solid particles or liquid 6 arethrown to the outside of the cylinder 1 and separating cone 4 whilelighter liquids or gas 8 concentrate at the inner part of the cylinderand cone. The heavier fraction 6 is collected in an annular ring anddischarged through a pipe 5. The lighter fraction 8 at the inner portionof the separating cone is collected and discharged by a pipe 7.

Applicant has devised improvements on the conventional liquid vortexseparator with intensified vortex forces.

DESCRIPTION OF THE INVENTION

In one form therefore the invention is said to reside in a liquid vortexseparator including a vortex tube with a feed end and an outlet end, animpeller in the feed end to impart a rotational motion to liquid withinthe tube, a feed inlet adjacent to the feed end, a separating cone atthe outlet end, an annular collecting ring in the separating cone, aheavy solids outlet from the separating cone and a liquid discharge pipeextending axially from the separating cone, characterised by a feedcylinder of larger diameter than the vortex tube at the feed end, thefeed cylinder being connected to the vortex tube by a reducing cone andthe impeller and the feed inlet being in the feed cylinder.

Preferably the feed end inlet feeds tangentially into the feed cylinder.

The impeller may have three or more vanes connected by spokes orcircular plate to a drive shaft and the vanes of the impeller may beoriented or shaped so as to impart a motion to the feed material in thedirection of discharge end of the liquid vortex separator.

The slope of the reducing cone may be proportional or hyperbolic inshape and the angle of the wall of the reducing cone can be in the rangeof 45 to 10 degrees to the longitudinal axis of the vortex tube.

The slope of the separating cone may be proportional or hyperbolic inshape and the slope of the separating cone can be in the range of 45 to10 degrees to the longitudinal axis of the vortex tube.

The discharge end of the separating cone terminates in a dosed cylinderconcentric with the separating cone to collect the heavy solid particlesor heavy liquid into a discharge pipe.

There can be further included an open cylinder at the discharge end ofthe separating cone whereby to collect middlings into a middlingdischarge pipe.

The liquid discharge pipe can be flared at its feed end and is locatedin and concentric with the separating cone to collect light liquidfractions or gas and to discharge them from the liquid vortex separator.

The annular cylinder collecting heavy fractions and the cylindercollecting the middlings may be adjustable in position along the axis ofthe separating cone. Adjustment of the position of the annular cylindercan be by means of a screw or hydraulic system.

There can be further included a feed tank to enable a constant supply tobe supplied to the liquid vortex separator. The feed tank can include anagitator and a baffled compartment to receive light product from theliquid vortex separator and a bottom discharge to the liquid vortexseparator.

The feed tank may also include provision for addition of reagents andalso for heating or cooling. Heating or cooling may also be added to theliquid vortex separator.

There can be further included at least one microwave generator adaptedto feed microwave entry at several points in the separating cylinder.Microwave energy can be provided a frequency from 800 to 22,000megahertz and is delivered to the separating cone via a wave guide and amicrowave window or via co-axial cable and antennae.

There can be further included means to apply magnetic energy to thevortex tube. The magnetic energy can be applied by an electromagnet or apermanent magnet.

There can be further included means to apply unipolar activation to theinterior of the vortex tube.

Hence it will be seen that the various embodiments of the inventionconsist generally of one or more of three parts as follows:

-   -   Modifications to the liquid vortex separator to improve its        separating efficiency, and    -   A feed tank to ensure the continuous efficient operation of the        liquid vortex separator and    -   Fitting the liquid vortex separator with microwave generators,        or with electrodes, or with magnets to carry out certain        specific functions.

BRIEF DESCRIPTION OF THE DRAWINGS

A description of the invention is given below referring to diagrams toaccurately describe the embodiments of the invention.

In the drawings:

FIG. 1 shows a prior art vortex separator;

FIG. 2 shows a first embodiment of liquid vortex separator according tothe invention;

FIG. 3 shows an alternative embodiment of the discharge end of thevortex separator according to this invention;

FIG. 4 shows a cross sectional view of the inlet end of the vortexseparator shown in FIG. 2

FIG. 5 shows a schematic flow diagram for a liquid vortex separationsystem according to the invention;

FIG. 6 shows an improvement to the liquid vortex separator of FIG. 2according to another aspect of the invention;

FIG. 7 shows an alternative improvement to the liquid vortex separatorof FIG. 2 according to another aspect of the invention; and

FIG. 8 shows another improvement to the liquid vortex separator of FIG.2 according to another aspect of the invention.

DESCRIPTION OF PREFERRED EMBODIMENT

FIG. 2 is a diagram describing the advanced liquid vortex separatoraccording to one embodiment of the present invention.

The basic components of this vortex separator are the drive 15 providingrotational motion to the impeller 13 located in a feed cylinder 12, areducing cone 14 between the feed cylinder 12 and a separating cylinder16, a separating cone 17 and a means of discharging the separatedproducts generally shown as 10. FIG. 2 shows the vortex separator in thehorizontal position but it may also be oriented in a vertical orinclined position.

Feed that may be a mixture of liquid and fine solid, or liquids ofdifferent specific gravity or a mixture of gas and liquid is introducedinto the feed inlet 11 and guided to a tangential entry into the feedcylinder as shown in more detail in FIG. 4. The feed cylinder may have adiameter of 150 to 1,500 millimeters or more depending on the nature ofthe application and the capacity required. The impeller 13 gives thefeed slurry a rotational motion. The impeller consists of three or morevanes connected by spokes to the drive shaft. Alternatively, the vanesmay be connected to a circular plate close to the rear of the cylinderthat is connected to the drive shaft. The vanes are oriented or shapedso that they impart a motion to the slurry in the direction of thedischarge end. The rotation speed of the slurry is increased as itpasses through the reducing cone 14. The slope of the reducing cone maybe as high as 45 degrees to the longitudinal axis of the separatingcylinder to as low as 10 degrees to the longitudinal axis of theseparating cylinder. The separating cylinder allows for more separationof the components of the slurry. The length of the separating cylinder16 can vary depending on if the solid is coarse and heavy requiring ashort length or none at all to a long length if the solids are fine andhave a low difference in specific gravity to the liquid it is carriedin.

The slurry subsequently transfers from the separating cylinder 16 to theseparating cone 17 where more intense separating forces are applied. Theslope of the separating cone 17 may be as high as 45 degrees to thehorizontal to as low as 10 degrees to the longitudinal axis of theseparating cylinder. Generally, coarse particle separation is favored bya sharp angle such as 35 degrees while fine particle separation isfavored a flatter angle such as 15 degrees.

Products are collected and discharged separately at the end of theseparating cone in at least two separate fractions. The heaviest andcoarsest particles 26 are collected in an annular ring 18, the middlings25 are collected in another annular ring 20 which is within the annularring 18 and the liquid with very fine solids 24 are collected by pipe22. Pipe 22 may be an ordinary pipe but it may also be flared at thefeed end as shown in FIG. 3. Pipe 22 may also be adjustably mounted sothat it can be moved further into or out of the separating cone 17. Forsome separation systems the use of the annular ring 20 to collect themiddlings 25 may not be necessary.

FIG. 3 shows an alternative embodiment of the discharge end of thevortex separator according to this invention In this embodiment theannular collecting ring 20 is connected to outer annular ring 18 andboth may be moved further into or out of the separating cone 17 throughan adjustable arrangement consisting of screws or hydraulics 27 andsliding seals 19. This allows the cut between middlings 25 and heavycoarse particles 26 to be varied during the operation of the liquidvortex separator. This adjustment may be made automatically duringoperation by measuring the density of the heavy fraction 26. The speedof the drive 15 for the impeller 13 may also be varied to maintain thedesired properties of the heavy coarse particles 26.

Cooling and heating including the provision of insulation onto theexternal surfaces of the liquid vortex separator may be provided.

The components of the liquid vortex separator may be made of theappropriate materials or provided with protective coating such asnatural and synthetic rubber and plastics such as Teflon andpolyurethane to meet various applications that are abrasive andcorrosive.

It has been found that the liquid vortex separator will operate moreefficiently if a constant rate of feed volume is achieved. This may beachieved in this invention by the arrangement shown in FIG. 5.

FIG. 5 shows a schematic flow diagram for a liquid vortex separationsystem according to the invention and includes a feed tank 31 fittedwith a baffle 33 and the system involves circulating the middlings andlight stream products from the liquid vortex separator. Raw waste orfeed slurry 30 is fed into the feed tank 31 fitted with or without anagitator 32. Middlings 25 from the vortex separator are circulated tothe feed tank 31 with or without the aid of a pump. Reagents 34 may beadded to the feed tank. The mixed slurry 9 is fed into the vortex liquidseparator inlet 11. The thick slurry 26 is the final product for thenext stage of processing such as filtration or microwave drying. Thelight product stream 24 is returned to baffled section of the fed tankwith or without the aid of a pump where part of it is recycled to theliquid vortex separator and the rest is discharged from the feed tank asthe relatively clear product 24. By the use of the feed tank 31 theliquid vortex separator will function efficiently even if there is avariation in the feed rate of the raw feed 30.

In the operation of the liquid vortex system, the light fraction or theheavy fraction from the first liquid vortex system may be the feed toanother vortex system to achieve the desired result for a particularapplication.

Reagents 34 may be added in the feed tank 31 to flocculate the solids orto create certain effects or chemical reactions in the liquid vortexseparator.

Jackets 35 may be placed around the reducing cone 14 and separatingcylinder 16 as well as to other components of the separator to provideheating, cooling or insulation as required for specific processes.

FIG. 6 is a diagram showing the liquid vortex separator fitted withmeans for microwave energy to be introduced into the separatingcylinder. The magnetron 40 generates the microwave that are transmittedby a co-axial cable or microwave guide 41 to a microwave antennae orwindow 42 into the separating cylinder 16 of the liquid vortexseparator.

FIG. 7 is a diagram showing electrodes fitted to the liquid vortexseparator. The function of these electrodes is to remove anode or addcathode electrons to the liquid or substances in the liquid inaccordance with our U.S. Pat. No. 5,882,502 to produce a desired effector chemical reaction. The solution electrode cylinder 52 is connected tolead 50 connected to the solution electrode of the anode or cathode. Theseparating cylinder 16 is a conductor and becomes the anode or cathodeconnected to the lead 51. The electrodes are therefore adapted toprovide unipolar activation to the liquid passing through the liquidvortex separator.

FIG. 8 is a diagram showing magnets fitted outside of the separatingcylinder 16 and separating cone 17. The separating cylinder andseparating cone must be made of material that allows magnetic forces topass with minimum resistance. The magnets 60 may be permanent magnets orelectromagnets and are arranged so that there are two or more sets alongthe circumference of the separating cylinder 16 and the separating cone17.

These accessories of the liquid vortex separator are aimed at using theliquid vortex separator in the processing and purification of liquids.

1. A liquid vortex separator including a vortex tube with a feed end andan outlet end, an impeller in the feed end to impart a rotational motionto liquid within the tube, a feed inlet adjacent to the feed end, aseparating cone at the outlet end, an annular collecting ring in theseparating cone, a heavy solids outlet from the separating cone and aliquid discharge pipe extending axially from the separating cone,characterised by a feed cylinder of larger diameter than the vortex tubeat the feed end, the feed cylinder being connected to the vortex tube bya reducing cone and the impeller and the feed inlet being in the feedcylinder.
 2. A liquid vortex separator as in claim 1 wherein the feedend inlet feeds tangentially into the feed cylinder.
 3. A liquid vortexseparator as in claim 1 wherein the impeller has three or more vanesconnected by spokes or circular plate to a drive shaft.
 4. A liquidseparator as in claim 3 wherein the vanes of the impeller are orientedor shaped so as to impart a motion to the feed material in the directionof discharge end of the liquid vortex separator.
 5. A liquid vortexseparator as in claim 1 wherein the slope of the reducing cone isproportional or hyperbolic in shape.
 6. A liquid vortex separator as inclaim 1 wherein the angle of the wall of the reducing cone is in therange of 45 to 10 degrees to the longitudinal axis of the vortex tube.7. A liquid vortex separator as in claim 1 wherein the slope of theseparating cone is proportional or hyperbolic in shape.
 8. A liquidvortex separator as in claim 1 wherein the slope of the separating coneis in the range of 45 to 10 degrees to the longitudinal axis of thevortex tube.
 9. A liquid vortex separator as in claim 1 wherein thedischarge end of the separating cone terminates in a closed cylinderconcentric with the separating cone to collect the heavy solid particlesor heavy liquid into a discharge pipe.
 10. A liquid vortex separator asin claim 1 further including an open cylinder at the discharge end ofthe separating cone whereby to collect middlings into a middlingdischarge pipe.
 11. A liquid vortex separator as in claim 1 wherein theliquid discharge pipe is flared at its feed end and is located in andconcentric with the separating cone to collect light liquid fractionsand to discharge them from the liquid vortex separator.
 12. A liquidvortex separator as claim 1 wherein the annular cylinder collectingheavy fractions and the cylinder collecting the middlings are adjustablein position along the axis of the separating cone.
 13. A liquid vortexseparator as in claim 12 wherein the adjustment of the position of theannular cylinder is by means of a screw or hydraulic system.
 14. Aliquid vortex separator as in claim 1 further including a feed tank toenable a constant supply to be supplied to the liquid vortex separator.15. A liquid vortex separator as in claim 14 wherein the feed tankincludes an agitator and a baffled compartment to receive light productfrom the liquid vortex separator and a bottom discharge to the liquidvortex separator.
 16. A liquid vortex separator as in claim 14 whereinthe feed tank includes a reagent addition arrangement.
 17. A liquidvortex separator as in claim 16 wherein the microwave energy is providedat a frequency from 800 to 22,000 megahertz and is delivered to theseparating cone via a wave guide and a microwave window or via co-axialcable and antennae.
 18. A liquid vortex separator as in claim 14 whereinthe feed tank includes an arrangement to add heating and cooling.
 19. Aliquid vortex separator as in claim 1 further including at least onemicrowave generator adapted to feed microwave entry at several points inthe separating cylinder.
 20. A liquid vortex separator as in claim 1further including means to apply magnetic energy to the vortex tube. 21.A liquid vortex separator as in claim 20 wherein the magnetic energy isapplied by an electromagnet.
 22. A liquid vortex separator as in claim20 wherein the magnetic energy is applied by a permanent magnet.
 23. Aliquid vortex separator as in claim 1 further including means to applyunipolar activation to the interior of the vortex tube.
 24. A liquidvortex separator as in claim 1 further including an arrangement to addheating and cooling to the separating cylinder.